Dbill holder



No. 80,386. PATENTED JULY 28,1868.

- @BURLBIGHu- DRILL HOLDER.

CHARLES ,BURLEIGH, OF FITCHBURG, MASSACHUSETTS.

Letters Patent No. 80,386, un ainl 23, .1868.

, mrnovsn DRILL-HOLDER.

I flitegctihtlc mm It in inst-Eaters ifiartemtnh matingtnt at ttettuie.

TO ALL wHoM IT MAY concerns:

Be it known thntiI, OHARLESBURLEIGH, of Fitchb'urg,in the county' of Worcester, and State of Mnssnchu setts, have invented'nn Improved Holder or Chuck for holding such drills as are used in stone-drilling machines; and I do hereby declare that the following, tnkeniir connection with the drawings which accompany end forin pnrt of this'specificetion, is a description of my invention sufiicientto enable those skilled in the nrtlto practise it.

The drills used in stone-drilling machines'huve been variously secured in mnndrels carrying them, as, for

example, screw-threads have been out upon the butt of the drill, which has then been'sorewed into the screwtepped hole made in the mandrel, or the drill has been keyed in the mandrel, and various other devices have been employed, all of which heveifailed, to a greater or less extent, in firmly holding together the drill and mandrel, under the concussions resulting from the violent and rnpidblows' given'by'the drill uponnninterinl so little yielding as stone.

The drawings arein illustration of nnenrbodiment ofimy inventionv I Figure 1 being a; side-view of ei' mrndrel'provided withl'my'improved holder for'the drill, and v Figure 2 being a. cross section of the nendrel and drill, taken through the chuck orholding-device onithe' line m, fig- 1. 1

The mandrel, a, is bored concentrically with its axis, to lit the butt of the' drill, b, which is'intended to .botto'm in the hole drilled in the mandrel, n3 is shown in dotted lines in fig. 1. i

The end of. the mandrel is enlarged, to compensate for .loss of material, renioved by a. transverse bore intersecting the longitudinal bore, and in the transverse here is fitted a plug or cylinder, c which nt oneend is made as a screw, provided with the nut d.

the hole in which the drill-butt fits.

I In making my-improvecl chuck or holder, I make the hole for the plug 0, and fit the plug in the hole before I drill out the longitudinal hole, so that a portion of plug c has formed in its body a. portion of the outline of I Now, it'will be seen, that, after the drillis placed inthe longitudinal hole, s very slighteu'dwise movement I of the plug c-,- occasioned by tightening the'nut d, will bind the driILshank, almostboyonyl possibility of ac'cidental removal. 2'

To guard against the loosening oi the nut cl, by turning, under the influence of the jars or shocks on the" I, drill, I slightly bend the steel washer e, so that it may act as a spring under the nut, the effect of which is to f prevent the nut from loosening. I

Instead of bending the washer-,1 sometirnes sent it on a. sub-washer of leather, which has-n yielding prop ertyfwhich serves the purpose of the bent spring-washer,

I, claim a. drill-holding chuck, constructed-with a transverse plug crossing the socket-hole for the. drill-butt,

having a portion of the transverse plug, corrcspondin'g' with the perimeter of the socket-hole,removed, and hnving a screw and nut; or equivalent means, for giving endwise movement to the plug, all substantially es and for the purpose set'fo rt-h. H V CHARLES BURLEIGH.

Witnesses:

HILAND C. IIrrcncocs J[ M. GRAHAM. 

